Ecological isn't the reason why they're racing E-class cars, be it these trucks (sigh...) or Formula cars. Probably all kinds of car-brands are going to put their names on these cars too and use it for promotion more than anything.
It's not as bad as Lamborghini Urus racing class, that really gave me a wtf moment.. Next is the Jaguar iPace racing class, I mean..
I like all kinds of motorsports, but mostly the ones where the cars are actual race cars and built as such. Here though they even mention 'SUV' on their website which makes me want to skip this class too (no, lineup isn't everything).